1. Field of the Invention
The present invention relates to a medical apparatus, and in particular, it relates to a method and an apparatus for breaking up calculi in urinary intracavity.
2. Description of the Related Art
Calculi in a urinary system usually include renal calculus, ureter calculus, bladder calculus and urethra calculus, which belongs to a frequently encountered disease and a commonly encountered disease. There are several methods to treat calculi in the urinary system, such as, pharmaceutical treatment, treatment of calculi with extracorporeal shock wave lithotripsy, open operation for treatment, lithotrity treatment of calculi with the endoscope which are adapted to specific symptom of the diseases. With the development of the lithotrity treatment of calculi with the endoscope, it is increasingly adopted to treat a good variety of symptoms of the disease. There are a number of methods for treating the calculi with the endoscope, such as electrohydraulic shockwave lithotripsy, pneumatic ballistic lithotripsy, laser lithotripsy, ultrasonic lithotripsy, etc. However, the electrohydraulic shockwave lithotripsy falls into disuse due to its low speed and poor efficiency. Pneumatic ballistic lithotripsy and laser lithotripsy have the disadvantages of generating bulky stone fragments, picking up the stone fragments by repeated water flush or by a jaw during the operation, owning a relatively slow operation process, and easily causing residual stone fragments. Ultrasonic lithotripsy usually has a risk of massive hemorrhage because it requires a broad passage (of usually lager than 22F), furthermore, to adamantine calculi, the ultrasonic lithotripsy has an extraordinary low lithotripsy speed and efficiency and even encounters failure.